[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Another Alxasaurus query
Better tidy up the last chapter in case anything starts next week:
Tom said on 2nd Feb 99:
>Now, to be fair, none of these studies currently *published* test what is
>needed to refute Olshevsky's assertion: namely an analysis where
>prosauropods and/or ornithischians are also included among the ingroups, so
>that (in terms of the search mechanics) recovery of a
>prosauropod-therizinosauorid clade is at least possible.
The word "refute" is commonly taken in scientific circles to imply absolute
certainty, or at least as certain as we can get about anything (as in "The
sun will rise tomorrow").
Morphological cladistic evidence is known to be imperfect. Probably the
best example of this is the placing by morphological cladistics of chimps
closer to gorillas than to humans, whereas we believe, from molecular data,
chimps to be closer to us. Only one example is required to reduce the
status of morphological cladistic evidence from some kind of absolute law to
just another heuristic, though of course we have a multitude of refutations
for it. These are *proper* refutations of its absolute reliability.
Maybe, with a high ratio of specimens to character changes, and using
molecular data, we might thoroughly convince ourselves of some
relationship - but to say a result depending entirely on a morphological
cladistic analysis of - of all things - therizinosaurs, *refutes* anything,
is too take a long walk in the direction of scientific unconventionality.